The set works as it should. I bought this tool to replace pistons and rings on a Toyota 2AZ engine. The quality was on par with anything else in GearWrench. This was bought to replace a better known brand that was inferior in comparison to this set. This kit blew the OTC kit out of the water. Make sure the compressor ring lies evenly over the entire surface of the cylinder block to keep the rings pressed against the cylinder wall.